1. Field of the Invention
The present invention relates to a socket for electrical parts or components for detachably holding an electrical part such as a semiconductor device (hereinafter, referred to as an xe2x80x9cIC packagexe2x80x9d).
More particularly, the present invention relates to a socket for electrical parts improved in a wiping effect of a contact pin contacted to a terminal of the electrical part and separated therefrom.
2. Relevant Art to the Invention
In a known art, as a conventional xe2x80x9csocket for electrical partsxe2x80x9d of this kind, there is provided an IC socket for detachably holding an IC package as xe2x80x9celectrical partxe2x80x9d.
The IC package, which is called such as gull-wing type, is provided with a package body having a substantially rectangular parallelepiped structure and with a plurality of IC leads as xe2x80x9cterminalsxe2x80x9d. The plurality of IC leads project from two sides of the package body, which are opposite to each other, towards the side thereof so as to provide a crank shape.
On the other hand, the IC socket, partially as shown in FIG. 11, has a socket body 1 on which a receiving portion 1a is formed. The IC package is mounted on the receiving portion 1a so as to be received in the socket body 1. The IC socket is also provided with a plurality of contact pins 2 contacted to IC leads of the IC package. The contact pin 2 comprises a movable contact piece 3 and a stationary contact piece 4 and the movable contact piece 3 is formed with a movable side contact portion 3a which is contacted to an upper surface of the IC lead and separated therefrom. The stationary contact piece 4 is formed with a stationary side contact portion 4a which is contacted to an lower surface of the IC lead.
Moreover, an upper operation member is provided for the socket body so as to be movable vertically (upward and downward) with respect to the socket body. When the upper operation member is moved downward towards the socket body against the urging force of the movable contact piece 3 of the contact pin 2 or the like, an operation piece, which is not shown, of the movable contact piece 3 of the contact pin 2 is pressed outwardly by a cam portion. The pressed operation piece makes elastically deform a spring or elastic portion, which is not shown, of the movable contact portion 3 of the contact pin 2 so that the movable side contact portion 3a is moved away from the IC lead. In addition, when the upper operation member is moved upward, the movable side contact portion 3a is returned so as to be contacted on the upper surface of the IC lead, thereby pressing it. As a result, the IC lead is clamped by the movable side contact portion 3a and the stationary side contact portion 4a whereby the contact pin 2 and the IC lead are electrically conducted.
On the other hand, while the IC package is not mounted on the receiving portion 1a, as shown in FIG. 11, the movable side contact portion 3a is contacted to the stationary side contact portion 4a so that the stationary side contact portion 4a provides a seat portion of the movable side contact portion 3a. When the movable side contact portion 3a is contacted to the stationary side contact portion 4a, that is, when the elastically deformed movable contact portion 3 is returned so that the movable side contact portion 3a is contacted to the stationary side contact portion, the movable side contact portion 3a is slid on the stationary side contact portion 4a from a position, which is shown as a chain double-dashed line in FIG. 11, to a position, which is shown as a solid line in FIG. 11, by a distance L1. Thus, the contact portion A of the movable side contact portion 3a to the stationary side contact portion 4a is slid by the distance L1 so that a solder adhering to the movable side contact portion 3a by contacting the IC lead is wiped (eliminated).
The effect of wiping the solder adhering to the movable side contact portion 3a is improved by adjusting a roughness of the upper surface of the stationary side contact portion 4a. 
However, in the conventional socket described above, because the contact portion A of the movable side contact portion 3a is lineally contacted to the stationary side contact portion 4a and the upper surface of the stationary side contact portion 4a is made flat, even if the movable side contact portion 3a is slid on the stationary side contact portion 4a, the contact portion A is only wiped, and accordingly, there is a possibility that the wiping effect is achieved in only the extremely short area.
An object of the present invention is to eliminate defects or drawbacks encountered in the prior art mentioned above and to provide a socket for electrical parts, which is capable of making longer a wiped width of the movable side contact portion.
In order to achieve such object, according to one aspect of the present invention, there is provided a socket for an electrical part comprising:
a socket body in which an electrical part is received;
a contact pin provided for the socket body and formed with a movable contact piece, the movable contact piece being provided with a first contact portion at one end thereof, the first contact portion being contacted to a terminal of the electrical part or separated therefrom;
a mount (seat) portion on which, without the electrical part being received in the socket body, the first contact portion is mounted; and
a bent portion formed on the seat portion so that the first contact portion is adapted to be slid on the bent portion.
According to this aspect of the present invention, since the bent portion is formed on the mount portion on which the first contact portion is seated so that the first contact portion is adapted to be slid on the bent portion, thereby wiping the solder adhering to the first contact portion, it is possible to make longer the wiped width of the first contact portion, the wiped width of the first contact portion ranging over a long distance.
In preferred embodiment of this aspect, the terminal has one surface and other surface opposite to the one surface, the first contact portion has one surface contacted to the one surface of the terminal and separated therefrom, the contact pin is provided with a stationary contact piece having a second contact portion at one end thereof, the second contact portion having one surface contacting to the other surface of the terminal, and wherein the mount portion is formed on the one surface of the second contact portion.
A preferred embodiment of this aspect further comprises an operation member provided for the socket body so as to be movable with respect to the socket body, and the socket body has a receiving portion on which the electrical part is mounted to be received, the movable contact piece is moved towards the receiving portion of the socket body or withdrawn therefrom in accordance with the movement of the operation member, the first contact portion of the movable contact piece being slid on the bent portion while the movable contact piece is moved towards the receiving portion.
According to these preferred embodiments of this aspect of the present invention, the mount portion is formed on the one surface of the second contact portion of the stationary contact piece, making it possible to wipe the first contact portion by the slide between the first and second contact portions.
This aspect of the present invention has an arrangement that the mount portion is formed on the socket body.
According to the arrangement of this aspect of the present invention, even in the case where the contact pin having, that is, the one-point contact structure, it is possible to make longer the wiped width of the first contact portion.
This aspect of the present invention has an arrangement that the bent portion is a convex portion formed on one surface of the mount portion on which the first contact portion of the movable contact piece is contacted.
According to the arrangement of this aspect of the present invention, it is possible to increase the contact pressure between the convex portion and the first contact portion, thereby further improving the wiping effect of wiping by the convex portion the solder adhering to the first contact portion.
In preferred embodiment of this aspect, the convex portion has a substantially arc shape in substantially vertical cross section thereof along a sliding direction of the first contact portion of the movable contact piece.
According to the preferred embodiment of this aspect of the present invention, because the convex portion has a substantially arc shape in substantially vertical cross section thereof along a sliding direction of the first contact portion, it is possible to decrease a change of the resistance of the slide, thereby smoothly wiping the first contact portion.
In a preferred embodiment of this aspect, the convex portion has a substantially V-shape in substantially vertical cross section thereof along a sliding direction of the first contact portion.
According to the preferred embodiment of this aspect of the present invention, since the convex portion has a substantially triangular shape in substantially vertical cross section thereof along a sliding direction of the first contact portion, it is possible to efficiency wipe the solder adhering to the first contact portion of the contact pin by an uppermost pointed edge portion of the convex portion, thereby exhibiting a practically useful effect for improving the wiping effect.
This aspect of the present invention has an arrangement that the bent portion is a concave portion formed on one surface of the mount portion on which the first contact portion of the movable contact piece is contacted.
In accordance with the arrangement of this aspect of the present invention, since the first contact portion is intruded in the concave portion to make it possible to prevent the first contact portion from moving inside the socket body. As a result, when the movable contact piece is subjected to an external force from an outside of the movable contact piece to an inside thereof, it is possible to prevent the movable contact piece from coming off towards the inside thereof.
In preferred embodiment of this aspect, the concave portion has a substantially arc shape in substantially vertical cross section thereof along a sliding direction of the first contact portion.
According to the preferred embodiment of this aspect, because the concave portion has a substantially arc shape, it is possible to decrease a change of the resistance of the slide, thereby smoothly wiping the first contact portion.
This aspect of the present invention has an arrangement that the concave portion has a substantially triangular shape in substantially vertical cross section thereof along a sliding direction of the first contact portion.